[dwm] inconsistency

Well I notice, that the arrays are named in an inconsistent way.
So I'm going to rename Rule rule[] into Rule rules[], Layout
layout[] into Layout layouts[], and Key key[] into Key keys[] -
this way there is no clash with function names and the array
names are equal to the defines. So keep this in mind when
upgrading your config.h as well...

Regards,

-- 
 Anselm R. Garbe >< http://www.suckless.org/ >< GPG key: 0D73F361